custom_greetings.sc

/* scala-cli script 
   This script is published as part of the blog - https://ganeshchand.com/blog/scala-cli-getting-started
   The script demonstrates how to parameterize your scripts and share/run the script as github gist.
   How to run this script:
   scala-cli https://gist.github.com/ganeshchand/fa703cc5459aa92dd07210ea6d549765 -- "Scala is fun"
*/

// greet with good morning or good afternoon or good evening based on the time of the day
val hour = java.time.LocalTime.now.getHour
val greeting = hour match {
    case h if h < 12 => "Good Morning"
    case h if h < 16 => "Good Afternoon"
    case h if h < 20 => "Good Evening"
    case _           => "Good Night"
}

val defaultMessage = "let us live live in peace and harmony"
val message = if(args.isEmpty) defaultMessage else args(0)
println(s"$greeting World, $message!")